diff --git a/builtin/blame.c b/builtin/blame.c
index 5a67c202f0..01956c8081 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -2050,14 +2050,8 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	switch (userdiff_config(var, value)) {
-	case 0:
-		break;
-	case -1:
+	if (userdiff_config(var, value) < 0)
 		return -1;
-	default:
-		return 0;
-	}
 
 	return git_default_config(var, value, cb);
 }
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 07bd984084..8ed501f220 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -226,14 +226,8 @@ static const char * const cat_file_usage[] = {
 
 static int git_cat_file_config(const char *var, const char *value, void *cb)
 {
-	switch (userdiff_config(var, value)) {
-	case 0:
-		break;
-	case -1:
+	if (userdiff_config(var, value) < 0)
 		return -1;
-	default:
-		return 0;
-	}
 
 	return git_default_config(var, value, cb);
 }
diff --git a/builtin/grep.c b/builtin/grep.c
index 5c2ae94e55..dc6de83ab7 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -325,11 +325,8 @@ static int grep_config(const char *var, const char *value, void *cb)
 	struct grep_opt *opt = cb;
 	char *color = NULL;
 
-	switch (userdiff_config(var, value)) {
-	case 0: break;
-	case -1: return -1;
-	default: return 0;
-	}
+	if (userdiff_config(var, value) < 0)
+		return -1;
 
 	if (!strcmp(var, "grep.extendedregexp")) {
 		if (git_config_bool(var, value))
diff --git a/diff.c b/diff.c
index 84780fd5e6..3550c18e39 100644
--- a/diff.c
+++ b/diff.c
@@ -177,11 +177,8 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	switch (userdiff_config(var, value)) {
-		case 0: break;
-		case -1: return -1;
-		default: return 0;
-	}
+	if (userdiff_config(var, value) < 0)
+		return -1;
 
 	if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 		int slot = parse_diff_color_slot(var, 11);
diff --git a/userdiff.c b/userdiff.c
index 76109da4bc..1e7184f7f0 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -210,14 +210,7 @@ static int parse_funcname(struct userdiff_funcname *f, const char *k,
 	if (git_config_string(&f->pattern, k, v) < 0)
 		return -1;
 	f->cflags = cflags;
-	return 1;
-}
-
-static int parse_string(const char **d, const char *k, const char *v)
-{
-	if (git_config_string(d, k, v) < 0)
-		return -1;
-	return 1;
+	return 0;
 }
 
 static int parse_tristate(int *b, const char *k, const char *v)
@@ -226,13 +219,13 @@ static int parse_tristate(int *b, const char *k, const char *v)
 		*b = -1;
 	else
 		*b = git_config_bool(k, v);
-	return 1;
+	return 0;
 }
 
 static int parse_bool(int *b, const char *k, const char *v)
 {
 	*b = git_config_bool(k, v);
-	return 1;
+	return 0;
 }
 
 int userdiff_config(const char *k, const char *v)
@@ -246,13 +239,13 @@ int userdiff_config(const char *k, const char *v)
 	if ((drv = parse_driver(k, v, "binary")))
 		return parse_tristate(&drv->binary, k, v);
 	if ((drv = parse_driver(k, v, "command")))
-		return parse_string(&drv->external, k, v);
+		return git_config_string(&drv->external, k, v);
 	if ((drv = parse_driver(k, v, "textconv")))
-		return parse_string(&drv->textconv, k, v);
+		return git_config_string(&drv->textconv, k, v);
 	if ((drv = parse_driver(k, v, "cachetextconv")))
 		return parse_bool(&drv->textconv_want_cache, k, v);
 	if ((drv = parse_driver(k, v, "wordregex")))
-		return parse_string(&drv->word_regex, k, v);
+		return git_config_string(&drv->word_regex, k, v);
 
 	return 0;
 }